Inside-Out Spacetime

[Riogho]

Is it possible?

 

I thought of this when we were doing applications of integrals today (disk method, shell method bla bla) in calculus class. I was trying to figure out how you could get a negative volume. Would turning spaceitme inside out make that possible?

[Martin]

Is it possible?

 

I thought of this when we were doing applications of integrals today (disk method, shell method bla bla) in calculus class. I was trying to figure out how you could get a negative volume. Would turning spaceitme inside out make that possible?

 

In an older version of Loop Quantum Cosmology the universe turns inside out, at the bounce. The bounce is what replaces the singularity at Bang time.

This would be in papers 2001-2005, for instance by Bojowald.

The volume operator, a quantum observable, somehow reverses sign.

But since 2005 a different quantization has prevailed in which I believe this does not happen.

Here is a SciAm level popularization, to give the idea of the older version. It is unmathematical, misleading etc but it gives the idea of a quantum cosmology model turning space inside out.

don't believe popularizations, take if at all with grain of salt, but anyway:

http://arxiv.org/abs/physics/0407071

Edited January 7, 2009 by Martin

[Pete]

In an older version of Loop Quantum Cosmology the universe turns inside out, at the bounce.

What does it mean for a universe to be inside out??

[Mr Skeptic]

I'm rather confused as well. What distinguishes a positive volume from a negative volume?

[Martin]

Same except for orientation. See Vaas:

 

http://arxiv.org/abs/physics/0407071

 

Reverse orientation. Righthand screwthreads become lefthand. Maybe some particles become their antis.

Better, see if Vaas has anything to say.

Did you have a look?

http://arxiv.org/abs/physics/0407071

The title in German translates into The Inside-Out Big Bang

but that didn't sound right to the translator, so he called it

"The Inverted Big Bang". Trying to mean the same thing.

 

It was published in a magazine like SciAm, in Germany, with lots of illustrations. Unfortunately I can't link you to the illustrations with this English version.

 

We should really get Riogho to answer. It's his thread, and he is learning integral calculus. And in integral calculus, multivariate anyway, you can learn about orientation---how a volume can be negative. Not a big deal but really up to Riogho.

Edited January 8, 2009 by Martin